Furnace wall



May 19, 1931. o. NYGAARD FURNACE WALL Filed Feb. 4, 1926 2 Sheets-Sheetl v V INVEN'TOR. w W By j v H Wl. -7 TORNEY.

O. NYGAARD May 19, 1931.

FURNACE WALL 2 sheets-sheet 2 Fil'd Feb. 4, 1926 TORNE R..Y O MAM W N IVPatented May 19, 1931 UNITED STATES OSCAR NYGAARD, OF SAUGUS,MASSACHUSETTS FURNACE. WALL Application filed February at,` 1926. SerialNo. 85,916.

This invention relates to furnace walls, and more particularly to theconstruction of inner facings or linings for the walls of furnaceswherein the wall is subjected to an extreme and attimes an uneven heatsuch as pulverized fuel furnaces, although the invention i s highlyuseful also in any'furnace wherein the wall thereof is subjected to hightemperatures in part or in whole.

The main object of the invention is to provide a furnace wall that willsuccessfully avoid the difficulties encountered by reason of theunavoidable expansion of the brick lining due to the high temperaturesto which the wall is subjected. A subsidiary, but nevertheless animportant object, is the provision of a wall of which any impairedportion can readily be repaired without demolishing the adjoininguninjured portions and which is replaceable in whole or in part at aminimum of both time and expense.

My furnace wall, having these characteristic features, has the furtheradvantage that it can be built at a much less cost than other wallconstructions.

To the accomplishment of these objects` and such others as mayhereinafter appear,

as will readily be understood 'by those skilled in the art from thefollowing description, the invention comprises the novel constructionalfeatures, arrangement and combination of parts for furnace wallshereinafter described in their preferred form and then particularlypointed out in the appended claims.

The various features of the invention will best be understood from adescription of the best form at present known to me, illustrated in theaccompanying drawings, in which:

Figure 1 is a view, in erspective, of a portion of a masonry wall orfurnaces lined with an inner facing having the novel characteristics ofthe present invention, it being understood that the novel facing may,and preferably j does, completely cover the masonry wall;

Fig. 2 is a View of several tiers ofthe ywall in vertical section, themasonry portion thereof being shown broken away;

Fig. 3 lis a plan view, in horizontal section, through the complete wallbelow the line 3-3 of Fig. 1;

Figs. 4 and 5 are views, in perspective, of the two preferred types ofinter-engaging suspended brick aprons used in building a paneled facingconstruction;

Fig. 6 is a view, in perspective, of one type of filler brick that isinter-engaged with another type shown in Fig. 1 to form intermediatetiers between the tiers `of susspended or apron brick; and

Fig. 7 is a View, in perspective, of one type of support, to be builtinto the ermanent wall, on which a tier 'of the bric apron shown inFigs. 4 and 5 is removably suspended.

In the embodiment of the invention illustrated in the drawings 10indicates the permanent furnace wall which difiers from the usualmasonry wall by having built into it successive, vertically-spaced,horizontal rows of projecting supports which may conveniently be thebricks 12 (Fig. 7), although the invention includes within its scopeother equivalent supporting members combined with masonry or other typesof permanent wall. The bricks 12 are designed to removably support a,refractory inner facing or lining which covers the wall `10 from top tobottom. Each brick 12 convenientl has a projection at its outer edge inthe orm of an upwardly turned lug 13 which may have a convex upper faceastshow'n best in Fig. 7. It will be understood from the broken awayportion of Fig. 1 that the lining supports 12 of each series are spacedapart, providing for free circulation of air, behind the lining, betweenand about them.

Those skilled in the art are aware that the high temperature to which afurnace lining is subjected causes considerable expansion of its brickswith al consequent compression which frequently causes portions of thelining to collapse and require replacement. When the lining is built asamasonry wall,

i. e. with its bricks bonded together by high tem erature cement or fireclay, the repair work is not only difiicult but also slow and expensive.According to 'the present invention the lining that is suspended fromthe. projecting lining supports 12 is so constructed that no cement orother bond is required between the individual bricks and by the use ofslip-type or sealed joints at all meeting edges the bricks are assembledin such relation to'each other that the greatest degree of heat can beendured and the inevitable expansion can take place without injury. Atthe same time a free circulation of air, confined to the space behindthe apron, is maintained. The lining supports 12 are special 'bricksbonded into the permanent wall at regularly spaced intervals, inselected tiers or courses thereof, being thus located over the innerface of the permanent wall in horizontal and vertical alignment witheach other. This arrangement, with a like arrangement of suspensionmeans on the lining bricks, provides a highly important and novelfeature in air-cooled furnace wall construction which will be referredto after the constructional features of the lining have been explained.These features form highly important and novel characteristics of thepresent invention. Experts in the art will recognize, that with thedanger of deterioration from undue expansion eliminated, the initialcost can be reduced by the use of a much thinner brick; and that theabsence of a cementitious, fire clay or other'bond, when the bricks areconstrueted and assembled inthe manner now to be described, enablesspeedy repair of any portion of the lining.

The wall supports 12 provide for the suspension of the lining or facingthcreon, as shown best in Figs. 1 and 2. In building the lining, bricksare used having the novel characteristics shown in Figs. 4,-5 and 6.Each horizontal row ofthe projecting supports 12, sustains a tier oflining brick consisting of alternately arranged inter-engaging brickaprons 14 and 16 (Figs. 4 and 5). The relation of the vertical spacingof the horizontal rows of supports 12, to the vertical dimension of thebricks 14 and 16, purposely is such that after successive tiers formedof the apron bricks have been suspended, a space or horizontal channelis left between each tie'r. These channels are filled, and thecontinuity of the lining is completed, by introducing in these channelsalternately arranged inter-engaging filler bricks 18 and 20 (Figs. 1 and6).

The type of refractory lining just described in general terms, providesfor ready removability and replacement of any tier,

or of any portion of the lining as willvbe'` better understood from thefollowing detailed description. It will be observed that the verticalrows of lining brick, for example a row composed of alternatingjbrickaprons 14 and filler brick 18, or of brick aprons 16 and filler brick20, producela wall constructed of a series of adjoining vertical a body21 of the desired thickness,.two rear side-fianges 22 and abottom-flange 23 extending from the body material, a top-flange 24 in aplane at the rear of the body and preferably, although not necessarily,two depending suspension lugs 25 each of which may have its lower faceconcavely curved, or otherwise recessed to fit over the upwardlyprojecting lugs 13 on the supports 12. The lateral spacing of the lugs25 1s such that When a brick 14 is suspended one such lug seats andlocks on one edge of the support 12 while the other seats and locksonthe adjacent edge of the next support 12, the entire row being thussuspended vertically like an apron (see Figs. 2 and 3). Attention iscalled to the fact that the top and bottom edges of the brick aprons 14are oblique to the front and rear faces, the slope being inward anddownward after the brick is suspended (see Fig. 2). The brick aprons 16are generally similar to the brick aprons 14 except that each brick 16is provided with front side-flanges 26 instead of rear side-fianges. Thebottom and topfianges 23' and 24' on each brick 16 are the same as thelike flanges on a brick 14 except that they are shorter, and thesuspension lugs 25' are just the same in both shape and lateralspacing.Beveled top and bottom edges are provided on each brick 16 of the sameobliquity as those of a brick 14.

In building a suspended tier or lining apron from the bricks 14 and 16they are hung alternately by their rear lugs 25 and 25' on the supports12, the rear side-fianges of the bricks 14 underlying the frontsideflanges of the bricks 16, (see Fig. 1). The lugs 25 and 25'interlock firmly' with the lugs 13 and draw the rear faces of thesuspended bricks snugly against the end faces of the projecting bricksor other element 12 forming the supporting medium (see Fig. 2). Thebricks in any such tier are not forced together tightly laterally butare purposely hung with sufficient space left between them to allow forexpansion.

To complete the continuity of the lining the filler bricks 18 and 20 areseated in the horizontal channels already referred to, between the tiersformed of suspended brick, aprons 14 and 16. Each filler brick 20 (Fig.6) comprises a body 28 and arear key member. 30, the bottom edge ofwhich is flush with the `bottom edge of the body 28 (see Fig. 2) butwhich is so proportioned asto be both narrower and shorter than thebody. This provides a front top-fiange 31 and two front side-fianges 32.The length of the body 28 is the same as the width of the face of asuspended brick apron 16 since it is to be assembled in the verticalpanel of which the suspended brick 16 form a part. Likewise the lengthof the key member 30 is the same as that of the bottom-flange 23' on asuspended brick apron 16. The continuity of the vertical edges of thepanel are thus preserved. Each filler bri-ck 18 (shown only in Fig. 1)has a body 28' equal in length to the face of a suspended brick apron 14and its key member 30 is so proportioned as to provide two rearside-fi-.nges 33 and a front top-fiance 31'. this key being of the samelength as the bot-tom-fiange 23 on the suspended brick 1-1 (see Fig. 1).This preserves the continuity of the vertical edges of the panelcomposed of the suspended bricks 14 and filler bricks 18. The fillerbricks of both types have beveled top and bottom edges of the sameobliquity as the like edges on the suspended bricks.

In assembling the filler bricks with the lining aprons formed by thetiers of suspended bricks, first a filler brick 18 is seated betweeneach pair of vertically adjacent bricks let of several panels, and thena brick 20 is seated between each pair of vertically adjacent bricks 16of the ,adjacentpanels and so on until the facing is completed. Thefiller bricks are retained in these spaces by reason of the obliquity oftheir seating and by the top-flanges 2-1 and 24' of the apron brickswhich form rear stops. The vertical dimension of each filler brick issuch that it fits loosely in the channel between the tiers of suspendedbrick, thus allowing for expansion (see Figs. 1 and 2).

The loose joining of all the bricks used in forming the lining and theabsence of any bonding material whatever, permits free expansion of eachindividual brick both vertically and laterally, so that danger ofcrushing from this expansion is avoided and much thinner brick may beused than those now available for masonry or bonded linmgs.

It will be observed that the lugs 25 and 25' and supporting bricks 12maintain the novel suspended lining or facing spaced from the permanentfurnace wall 10 and, as heretofore stated, there is a free circulationof air through this space. This may be a forced circulation, if desired,the usual intake and exhaust passages through the Wall 10 beingprovided. The lugs for suspending the lining bricks are so spacedthereon as to provide both horizontal and vertical rows having the samespacing as the projecting lining supporting bricks bonded into thepermanent wall. The reason for locating the lugs on the suspendedmembers so that they also will be in horizontal and vertical alignmentwith each other after assembly, is that it aflords the importantprovision for building wholly vertical or wholly horizontal air passagesin the wall. The size and spacing of the lugs on the lining bricks andon the co-operating supporting bricks, both horizontally and vertically,are purposely designed and arranged as described so that it is onlynecessary to set out across the air space against the inner lining asufficient number of the standard size fire bricks, from which the outerwall is built, to close any selected series of spaces between the lugs.Thus free and unobstructed air passages extending in any directiondesired can be formed at will at very little expense since no extrashapes are necessary. Also, a wall thus constructed can readily besectioned ofl' in either dircction as may be advantageous for aparticular installation. For various reasons it is highly desirable tocirculate more, air through a certain area or section of the wall thanthrough another section, and it is equally important to be able tochange the circulation of air from horizontal to vertical, or viceversa, as this will avoid bypassing certain parts of the wall and resultin an even cooling of the lining. The overlapping flanges on the bricksof the facing will prevent the air in this circulation or coolingchamber from passing through the facing to the combustion chamber. If itis deemed advantageous to admit air into the combustion chamber or intothe fuel-bed, the bricks of as many tiers as inay be required for thispurpose may be perforated, as shown at 35 (Fig. 1) thus providing airejection passages from the air chamber behind the facing, to the fire.

Assuming that the lining has been in use and that a suspended brick, forexample the central brick 14 of Fig. 1, has become cracked for somereason, a replacement would be made as follows. First the filler brick20 above and to the left (or right) of the damaged brick is removed. Theabsence of cement and the short key member 30 of this filler brickpermits it to be removed without displacing any adjacent brick. Thefiller brick 18 directly above the damaged brick may then be slippedsidewise, until its flange 33 is cleared of the next overlapping flange,and finally removed. Suspended brick 16 to the left (or right) of thedamaged brick may then be forced upward until its lugs 25' are clear ofthe lugs 13Y on supports 12, when it may be removed. This givessufficient space to slide the damaged brick 14: sidewise, which ispermitted by the slip joint engagement at the meeting edges of thebricks, until its side fiange 22 is clear of the adjoining suspendedbrick 16 whereupon it may be lifted from the supports and removed.Replace- Vmerit is accomplished by reversing these steps. It will beobserved that if a suspended brick 16 is damaged it may be removed andreplaced by taking out only the filler brick above it.

Attention is especially called to the fact that the novel and improvedfurnace wall described, while of such thinness that it will heat andcool evenly, still provides ample constructional strength and yetsuccessfull eliminates structural strains because o the provision forexpansion of each unit of the wall` both horizontally and vertically.All parts of the wall, in large or small sections, are free to expandunder heat, thus preventing spalling at any point on the wall surfacehowever uneven the heat may be. The air space, permitting freecirculation of air in all directions behind the facing of refractorybrick, is of importance because the thin brick used may bethoroughlj/-cooled by this circulation and thus still maintain theirstrength. Of equal imortance are the overlapped expansion joints Whichprovide for a continuity of the heat absorbing lining and also make abonded brick construction unnecessary.

One of the features of the lining that adds materially to its efiiciencyand life resides in the mode of supporting the filler bricks. The fillerbricks, due -to their lposition just below each horizontal expansionjoint, are loose in the wall and, like the suspended bricks, arecomparatively thin. The usual vibration set up by the operation of thefurnace is suficient to shake any insecurely seated brick into thefurnace: Any appreciable accumulation of clinkers on the inner face ofthese filler bricks tends to overbalance them and would eventually tipthem into the furnace unless securely seated. The inclined surface atthe upper edge of the underlying row of suspended bricks upon which arow of filler bricks is supported and the complemental inclined surfaceat the lower edges of the filler bricks, co-act to cause the fillerbricks continually to gravitate outward, especially under jarring orvibration, and to counterbalance any excess weightfrom clinkers that maybe formed at the inner or fire face. Thus the entire lining remainsintact under allnormal conditions of furnace operation notwithstandingthat, apparently, some bricks are qute loose in the wall in order togain other advantages hereinbefore described.

Particular attention is called to the highly advantageous feature ofconstruction provided by the brick aprons which have been termed suchbecause of their manner of suspension, but itshould be distinctlyunderstood that the invention is not lmited to brick aprons having theillustrated suspension means but includes within its scope other meansfor removably supporting t e facing wall bricks in spaced relation tothe permanent furnace wall, accordingly in the appended claimscharacterizing features of the invention are set forth by theintentional use of generic terms and expressions inclusive of variousmodifications.

The nature and scope of the invention having been indicated, and itspreferred embodiment having been specifically described, what is claimedas new, is

1. In combination with a permanent furnace wall a refractory liningcomprising successive horizontal, verticall spaced tiers of bricks eachbeing4 one bric in height suspended from the permanent wall, rows of'filler bricks seated loosely in the spaces between said tiers, and meanson the rear edge of each suspended brick for retaining said fillerbricks within said spaces.

2. In a rcfractory lining for furnace walls a row of bricks comprisingadjacent pairs of bricks arranged horizontally, each pair composed ofone brick having two front side fianges and a rear bottom fiange and onebrick having two rear side flanges and a rear bottom 'lange whereby theadjacent side flanges of each two adjoining bricks are lapped afterassembly.

3. In a refractory lining for furnace walls a row of bricks com risingadjacent pairs of bricks arranged horizontally, each pair composed ofone brick having two front side fianges and a rear bottom flange and onebrick having two rear side flanges and a rear bottom flange whereby theadjacent side fianges of each two adjoining bricks are lapped afterassembly, and means on said briks for suspending them on the furnace wa,4. In a furnace wall an outer wall, a refractory lining consisting of aplurality of horizontal rows of brick units, each row comprising aplurality of unbonded units independently supported on said outer wallassembled with their lateral edges in overlapped, spaced relation,whereby to provide expansion joints permtting lateral expansion of eachunit independently of every other unit in the row, there also being likeexpansion joints between each row permitting vertical expansion of eachunit independently of every other unit.

5. A furnace wall construction comprising a permanent wall and anunbonded' refractory lining therefor composed of parallel verticalpanels each panel extending from top to bottom of the area to be linedand each panel being suspended on said permanent wall independently Aofeach other panel, and continuous, vertical sealed expansion jointsbetween said` panels formed by overlapping flanges at the meeting edgesof adjoining panels.

6. An expansible refractorj,7 brick lining for furnace walls consistingof a pluralty'of vertical panels side by side, each panel com- LQOOJISprising a plurality of brick units. each of which is aswide as thepanel, loosely engaging rabbeted horizontal edges on the adjoinunits ineach panel, and loosely engaging ra beted vertical edges on the abuttingunits of adjacent panels.

7. An expansible refractory brick lining for furnace walls consisting ofa plurality of vertical panels side by side, each panel comprising aplurality of brick units, the units composing the entire wall being ofsuch size and arrangement as to create continuous horizontal expansionjoints across the panels and continuous vertical expansion jointsbetween the panels, and each of said joints being sealed by looselyengaging rabbets on the edges of units which abut to produce saidjoints.

8. A permanent furnace wall, and a removable inner lining thereforadapted for operation under sustained high temperatures, said liningcomprising vertically disposed horizontal rows each composed of aplurality of brick. units each unit of each row having on its outer faceat least one suspension lug of lesser width than the width of the unit,whereby the lugs in any horizontal row will be in spaced relation toeach other, and single lining supporting brick members bonded into thepermanent wall, projecting inwardly therefrom and positioned thereoverto co-operate with said lugs for removably suspending each brick unit ofthe inner lining in substantially parallel spaced relation to thepermanent wall.

9. A furnace wall comprising an inner lining for operation undersustained high, temperature comprising a plurality of brick units eachhavin edges which loosely overlap the edges o all surroundin units topermit free expansion of each unit in every direction, a permanent wall,a plurality of projecting supports at the inner face of said permanentwall, and means on the lining units for enga ing said supports andholding the outer ace of the lining against the inner faces of thesupports and in spaced relation to the inner face of said permanentwall.

10. A furnace wall comprising a perranent wall having projecting liningsupporting bricks at its inner face, said supporting bricks being spacedapart both vertically and horizontally forming horizontal .and verticalrows of spaced supports, an inner lining -of refractor bricks and meanson some of the bricks o said lining for suspending them from and infront of said supports providing continuous vertical and horizontal airpassages between said limng and permanent wall.

11'. A furnace wall construction comprising a permanent masonry wall anda lining consisting of horizontal rows of relatively thin unbondedrefractory brick spaced from' the inner face of said permanent wall,said permanent wall being constructed of horizontal rows of bonded brickcertain of said rows having bonded therein projecting lining supportingbricks, there being a plurality of such projecting bricks in spacedrelation in each of said bonded rows, certain rows of said lining bricksbeing held in said spaced relation to said permanent wall by suspensionfrom said projecting bricks and certain other rows of said lining bricksbeing held in said spaced relation to said permanent wall by beinsupported upon said suspended lining bric rs.

12. A furnace wall construction comprising a permanent wall and anunbonded refractory lining therefor composed of parallel vertical panelseach panel consisting of a plurality of refractory bricks assembled incolumnar form, every other brick of said plurality being r'emo vablylsuspended on said permanent wall and each brick intermediate any twosuspended bricks'beino' slidingly supported on the suspended brikimmediately below it and spaced from the suspended brick immediatelyabove it.

13. In a furnace wall construction, a permanent wall and a refractorylining therefor comprising successivefi spaced, horizontal rows eachcomposed of unbounded single bricks suspended from the inner face ofsaid pernanent wall, and rows of unbonded single filler bricks, onefiller' brick directly overlying each suspended brick removablysupported intermediate said rows of suspended brick, all of the edges ofeach combination of suspended and filler bricks bein rabbeted foralapped engagenent of all o the meeting edges.

14. An inner facing for furnace walls comprising a plurality ofhorizontal, Vertically spaced tiers of brick each tier being one brickin height and each brick of a tier having a flange at both its upper andlower edge projecting into the spaces between tiers, and filler brickseated between said tiers and against the brick flanges.

15. A furnace wall having an outer wall provided with forwardlyprojecting lugs in horizontal rows, an inner lining comprsing verticallyspaced substantiallyhorizontal single rows of bricks suspended from saidouter wall lugs by at least one depending lug on each of the bricks, arow of unbonded filler bricks in the space between each row of suspendedbricks, and means for seating said filler bricksl on said suspendedvbricks in a manner to cause the filler bricks totend to gravitate towardthe outer face of the lining.

16. A furnace wall having an outer wall provided with forwardlyprojecting lugs in horizontal rows, an inner ining conprsing verticallyspaced substantially horizontal single rows of bricks suspended fromsaid 'Ill outer wall lugs by at least one depending lug on each of thebricks, a row of removable filler bricks in the space between each rowof suspended bricks all seated thereon, and said filler bricks formingany row also abuttin on their outer faces against portions o thesuspended bricks in any adjacent row.

17. In a furnace wall construction, a permanent wall and a refractorylining therefor comprising a plurality of separate, verticallyassociated units each composed of a single suspended brick andfa singlefiller brick the latter being removably seated above and on the former,and neans projecting from the inner face of said permanent wall and fromthe outer face of each suspended brick for interengagement to suspend`each unit from said permanent wall independently of each other unit, theproportion between the vertical spacing of said projecting means'on thepermanent wall and the height of the suspended brick being such as topermit the removal of a filler brick without disturbing the position ofeither adjacent suspended brick.

18. In combination with a permanent furnace wall a refractory liningcomprising successive horizontal, vertically spaced single rows ofbricks suspended from' the permanent wall, each row of suspended brickshaving its upper edge face in a plane that slopes downwardly andoutwardly, and rows of filler bricks of substantially the same thicknessas said suspended bricks seated loosely in said spaces, each row offiller bricks having its lower edge face in a plane to engage saidsloping upper edge face on a row of suspended bricks and having itsinner face in the plane of said lining.

19. A non-metallic furnace wall comprising a permanent brick wall havingspaced lining supportingbricks having flat inner ends projecting fromits inner face insuccessive horizontal rows, and a relatively thinlining comprising a plurality of assembled units each unit having meansfor suspension from said projecting bricks providing for an` engagementwith the inner ends of said projecting bricks whereby to space said thinlining from the permanent wall, there being expansion joints betweenadjacent sides of all the lining units so that each lining unit isexpansible in every direction independent of each other lining unit. a

20. In combination with a permanent furnace wall an inner liningtherefor constructed of successive horizontal rows of brick units eachunit comprising one brick suspended from a built in support on the innerface of the permanent wall and another brick resting on'and whollysupported by the suspended brick, and said rows of units being spacedIrom each other vertically to accommodate expansion.

21. A furnace wall construction comprisingra permanent wall having aplurality of built-in spaced projecting supports, and an 'inner liningcomposed of a plurality of horizontal rows of brick units each unitconsisting of a lower brick having a rear formation adapted to interlockwith at least one of said projecting supports and be rigidly supportedthereby and an upper brick unengaged with said projecting supports, thelower edges of said lower bricks in one row and the upper edges of saidupper bricks in the underlying row being overlappcd.

22. In a furnace wall a lining having a heat-resisting face comprising aplurality of refractory units assembled in wall formation having theiradjacent edges overlapped to form slip-type joints, and means forsupporting said units spaced from each other both horizontally andvertically to provide for free lateral and vertical expansion betweenany pair of said units.

23. A heat-resisting facing for permanent furnace walls comprised of aplurality of refractory bricks supported on the permanent wall and aplurality of refractory filler bricks, each filler brick being locatedvertically between two supported bricks, and the abutting edges of saidfiller and supported bricks above and below each filler brick beingoblique to the plane of the facing in such direction that the fillerbricks tend to gravitate outward when seated between each said twosupported bricks.

24. A heat-resisting facing for permanent furnace walls comprising aplurality of horizontal 'rows of members certain of which are refractorybricks supported on the permanent wall and others of which arerefractory filler bricks located between two rows of the supportedbricks, each row of filler bricks having its upper and lower edgessloping downwardly and outwardly and the rows of supported bricks aboveand below having their lower and upper edges respectively slopingdownwardly and outwardly in a like manner whereby each row of fillerbrick is caused to continually set more firmly into the facing, and eachof said supported bricks above having a depending portion to be engagedby the underlying filler brick to keep it in the plane of thelining.

25. 'A lining for furnace walls comprising a plurality of Verticalpanels each composed of a plurality of refractory bricks certain ofwhich are filler brick built into the panel at spaced intervals, theseating of said filler brck between adjacent refractory bricks of thepanel being on edge surfaces that slope downwardl'y and outwardly andagainst a rear flange on at least one of the adjacent refractory brickswhereby to retain said filler brick in place without bonding.

26. A furnace wall construction comprising a permanent wall and anunbonded refractory brick facing therefor, said permanent wall and saidfacing each having horizontally spaced members projecting substantiallyfrom theplane of the front face of the wall and from the plane of therear face of the facing for interengaging with each other and removablysuspending certain of the bricks of said facing in a plane in front ofthe members projecting from the permanent wall andv maintaining theentire facing spaced a substantial distance from the front face of thepermanent wall.

27. In a furnace wall construction a permanent wall and a refractorylining comprising successive spaced horizontal rows of unbondedoverlapping bricks, means for suspending said Mbricks from the permanentwall, and intermediate rows of unbonded overlapping filler bricks.

28. In combination with a permanent furnace wall, an inner facingtherefor consisting of a plurality of refractory members assembled inhorizontal rows as a wall, each row comprising a plurality of saidmembers and means for suspending independently the members in alternaterows from the permanent wall and for supporting the members in theremaining rows upon the members of said suspendedL rows, all jointsbetween said members being loose to provide for free expansion bothlaterally and vertically. I

29. A refractory lining for furnaces 'comprising bricks built insuccessive tiers and supported in a manner to provide horizontalexpansion joints between adjacent tiers, the filler bricks along the topof each tier and immediately below each expansion joint being seated ona downwardly and outwardly inclined surface to cause said brickscontinually to gravitate outwardly and to remain seated under the normalconditions of furnace operation tending to throw them manent wall underexpansion, there being expansion joints between adjacent meeting edgesof all the units so that each unit is expansible in every directionindependently of each other unit.

OSCAR NYGAARD.

inwardly, and means to restrain the filler bricks so seated fromgravitational movement out of the plane of the lining.

30. A furnace wallhaving an outer wall provided with forwardlyprojecting lugs in horizontal rows, an inner lining comprisin verticallyspaced horizontal single rows o bricks suspended from said outer walllugs by at least one depending lug on each of the bricks, and a singlerow of filler bricks in each space between adjacent rows of suspendedbricks.

31.l A furnace wall construction comprising a permanent wall and arefactory lining therefor composed of a plurality of brick' units, saidpermanent wall and said units having co-operating means engaging eachother by frictional contact only for independently supporting said unitsand permitting them to shift relatively to the per-

